When rebel soldiers overthrew the Mali government in 2012, coup leader Amadou Konare closed the border to everyone except the employees of Randgold Resources Ltd.

It’s pretty clear why. The company’s Loulo-Gounkoto and Morila mines were producing about 700,000 ounces of gold annually, valued at almost $1.2 billion. Randgold’s tax bill made it the biggest contributor to Mali’s economy. To keep the cash flowing, the new government quickly issued permits so workers could fly bullion out of the country to sell it on global markets.

“When you pay tax, you’re paying rent, and when you pay rent, the landlord doesn’t kick you out,” said Mark Bristow, Randgold’s chief executive officer, adding that his company delivers enough cash to Mali’s government to fund the entire civil-service payroll annually.

Africa has become the gold industry’s biggest growth story, despite the increased risks posed by political upheavals like a coup in Niger, Ivory Coast’s civil war or the Arab spring protests that spanned from Egypt to Morocco.

Excluding South Africa, where reserves are shrinking after a century as the world’s top producer, the continent boosted output by 68 percent since 2008, more than any other region, according to researcher GFMS, a unit of Thomson Reuters Corp. That’s paid off for some investors, with Randgold outperforming rivals as gold prices dropped.

The expansion was fueled by new mines in countries like Burkina Faso, Ivory Coast and Egypt, which all saw regimes change in the past five years. Many projects tapped rich gold deposits and used new technologies that unearth metal more cheaply than older mines forced to dig deeper or settle for lower-grade ore. The reduced costs allowed newer ventures to remain profitable even as bullion prices tumbled to a five-year low.

More Risk

“Mines in Africa need to have better geologic endowments to offset the extra costs and risks” associated with investing in the region, said Stephen Land, who manages $1.4 billion at Franklin Templeton Companies LLC in San Mateo, California, including the Gold and Precious Metals Fund.